The authority warns that users can look like they have overdosed on opioids, but they won't respond to naloxone and they can experience "speedy" or "trippy" symptoms with possible hallucinations.

A 2017 article in the New England Journal of Medicine says the drug caused a mass intoxication of 33 people in New York City in July 2016 and was described in the media as a "zombie" outbreak because of the appearance of those who took the drug.

The journal article says the drug was developed by Pfizer in 2009 and it is a strong depressant, which accounts for the "zombie-like" behaviour reported in New York.

Corneil says they don't like to use the zombie term because it can give people the wrong impression and what is important is they exercise caution when new substances come on the black market.

Corneil says they aren't aware of any deaths where the cannabinoid is the only substance.

"Often overdose deaths are caused by a mix of different substance together and we're not seeing any increase in overdose deaths related to this substance, relative to the impact of fentanyl, which is the major toxin we have in our drug supply right now."

Corneil says the discovery of the drug is a good example of the level of sophistication that both harm-reduction workers and users have been able to access in the province.

"This is the problem with criminalization, in that it takes away any of the safeguards that the system puts in place to ensure that people get the product they think they're buying and it hasn't been mixed with something else."

He says workers are seeing that users are becoming more aware that they need to have their illicit drugs tested and when they learn what's in their drugs, they make better decisions.

The testing machines at safe consumption sites look at a large database of drugs, which Corneil says is used for both research and by police.

"Many of them are unusual and rare and we're finding that manufacturers and suppliers are trying different new substances all the time ... trying to make a buck off people who are quite marginalized by the criminalized setting around them."